1. Technical Field
The present disclosure relates to a prepreg and a resin for preparing the same. More particularly, the present invention relates to a prepreg for adhering multi-layer circuit boards and a resin for preparing the same.
2. Description of Related Art
Technology continues to progress and this has resulted in circuit boards becoming increasingly complex. Circuit board structures are more complex because on increased design specifications, technology developments, or different applications of electronic products. The complicated structure of the circuit board, such as multi-layer circuit board, is often used in a printer head, a foldable mobile phone or a portable computer. Usually, the multi-layer circuit board is formed by overlapping several substrates with different features forms.
The substrate for the circuit board is divided into flexible substrate and rigid substrate. The flexible substrate is made from polyimide (PI), poly(ethylene terephthalate) (PET), poly(ethylene 2,6-naphthalate) (PEN) or a material containing rubber resin. The rigid substrate is made from epoxy resin.
Because the material of the flexible substrate and the rigid substrate is different, the prepreg is used to join the two substrates by thermocompression. However, during the thermocompression process, the resin of the prepreg often overflows from the edges of the two substrates and even more serious for manufacturing the circuit boards of the smaller electronic products. Hence, the reliability of the circuit boards is decreased. According to the standard of the Institute for Interconnecting and Packing Electronic Circuits (IPC), IPC-6013 3.3.1.3, the resin overflow from the edges of the substrates should be smaller than 1.5 mm (millimeter) to meet the reliability and manufacturing requirements.